Aircraft carry an on-board supply of engine fuel by means of fuel tanks defined by an internal volume of the aircraft's wing structure between the wing's upper and lower structural panels (known in the art as “skins”). Sometimes the wing tanks may include a fuel bladder located within the wing structure between the upper and lower wing skins so as to contain a desired quantity of fuel. In either the wet wing tank design or a bladder wing tank design, the wing tanks may be replenished with fuel by ground based refueling equipment (e.g., fuel tanker vehicles) through capped filler ports. In gravity fill systems, these capped filler ports are located in the upper wing skin and adapted to receive a filler nozzle associated with the refueling equipment.
It can therefore be appreciated that care must be taken to prevent the filler nozzle from being inserted into the filler port to an extent that would cause contact with, and thus potential damage to, the lower wing skin. In order to minimize or prevent such damage, aircraft manufacturers have developed devices located internally within the wing tank that limit the extent to which a filler nozzle may be inserted therein. These conventional devices tend however to be structurally complex (and hence expensive) since they typically include a cylindrical basket-type structure subjacent to the filler port designed to permit fuel to flow therethrough but to provide a structural barrier limiting the extent to which the fuel filler nozzle may be inserted into the wing tank.
It would therefore be desirable if more simplified structures and techniques could be provided which serve to protect an aircraft's gravity filled wing tanks from potential damage from a fuel filler nozzle. It is towards fulfilling such needs that the present invention is directed.
Broadly, the subject matter disclosed herein provides for protective devices for an aircraft fuel filler port associated with an aircraft wing tank that include a wall structure defining a dependent surface which slopes downwardly and laterally relative to the aircraft's longitudinal centerline. As such, a fuel filler nozzle when inserted into the fuel filler port will be angularly oriented laterally (preferably in an aircraft inboard direction). According to some preferred embodiments, the wall structure defines an arcuately concave surface which extends downwardly and laterally relative to the fuel filler port. In such a manner, the nozzle associated with refueling equipment is prevented from striking a lower wing skin of the aircraft wing when inserted into the fuel filler port. The protective device may include an upper annular collar for attachment to an upper wing skin of the aircraft wing so that the device is dependently fixed in coaxial alignment with the fuel filler port. The wall structure may include apertures for the purpose of weight reduction.
According to some embodiments, the wall structure of the device is comprised of a mirror image pair of wall members each defining an arcuate concave surface, the wall members being joined to one another along an edge corresponding to a central vertical plane of the device. The wall structure preferably defines a generally U-shaped forward edge.
An aircraft fuel filler port may include a cap ring defining a fuel filler port opening, a cap for closing the fuel filler port opening, and a protective device for dependent attachment to the cap ring. The protective device preferably has a wall structure extending downwardly into an aircraft's fuel tank and defining a surface, preferably an arcuately concave surface, which slopes downwardly and laterally relative to the filler port opening. As such, the sloped surface prevents the fuel filler nozzle from striking and potentially damaging a lower wing skin of an aircraft's wing when inserted into the fuel filler port. An aircraft may therefore be provided with a wing fuel tank which comprises such a fuel filler port.
These and other aspects and advantages will become more apparent after careful consideration is given to the following detailed description of the preferred exemplary embodiments thereof.